In his highly influential book On War (published posthumously in 1832), the military theorist Carl von Clausewitz asserted, 'war is simply the continuation of policy--or politics--by (or with) other means.' He argued that war could not be divorced from political life; its object was to impose one's will on the enemy by destroying his power to resist. To Clausewitz, war was a rational and legitimate means of furthering national interests even though he fully recognized its inherently violent and bloody nature, and the uncertainty of its outcome. He knew that states sometimes acted foolishly or recklessly, and he solemnly advised that:
No one starts a war--or rather, no one
in his senses should do so--without
first being clear in his mind what he
intends to achieve by that war and
how he intends to conduct it.
The Prussian well knew that the essence of war was uncertainty. He admitted that the 'fog' or 'friction' of war necessarily obscured and changed outcomes. So great were the variables of warfare that nothing could prepare the commanders to anticipate or counteract key events which shaped the course of a war. History, he thought, was as good a guide as any.
History does indeed provide a guide to those planning war, but it does not provide the lessons Clausewitz had in mind. If the unintended consequences of wars are examined, Clausewitz's maxim concerning the utility of war to achieve political ends is turned on its head. War turns out not to be a successful continuation of existing policy; most often, it produces an entirely new policy--frequently, quite the reverse of that originally embarked upon. The unforeseen consequences are usually more long-term than the intended outcomes and work in ways that counteract the original reasons for going to war. Nowhere is this better illustrated than through an examination of the major foreign wars of the United States since its earliest days.
The proclaimed reason the American colonists gave for resorting to arms against the English in April/May 1775 was to redress grievances and to guarantee themselves the historic 'rights of Englishmen'--particularly the right to be ruled and taxed by representatives of their own choosing. By July 1776 this goal had been transformed into one seeking the independence of the thirteen colonies from English rule and to creating a new nation-state, 'The United States of America', based on the ideas of the Enlightenment and, ironically, the 'Sacred Rights of Englishmen'. The turning point occurred in March 1776, when the English evacuated Boston and set up military headquarters on Manhattan Island, thereby hardening the resolve of those already determined to seek independence and converting those who had sought only greater freedom and political autonomy within the British empire.
There were several unexpected or unintended outcomes of the Revolutionary War, which ended in September 1783 with the Treaty of Paris after eight long years of fighting and the loss of around 25,000 American lives. The first was the extremely decentralized nature of the newly independent country. The thirteen largely autonomous and loosely federated states experienced chaos and impotence in the first years of the nation's history. This incapacity was felt most strongly in the areas of taxation and in the conduct of foreign relations. The lack of a national army led to a crisis in security due to the country's inability to 'defend' its frontier against attacks by Native Americans or to force the promised British evacuation of northwest forts. In 1787 the decentralized form of government for which the American revolutionaries had fought was discarded in favour of a centralized system. This made the president not only the head of state but the commander-in-chief of its armies, a move which granted him the right to conduct war--powers far greater than those of the 'despotic' British king, George III, whose rule had prompted the move for independence. …